1. Field of the Invention
The present invention relates to a useful lipid metabolism improving composition. More particularly, the invention relates to a useful lipid metabolism improving composition comprising S-(.alpha., .beta.-dicarboxyethyl)glutathione, which is a physiological substance, an ester or amide derivative thereof, or a pharmacologically acceptable salt thereof as an active ingredient.
2. Description of the Prior Art
Hyperlipidemia is regarded a risk factor for arteriosclerosis. It is known that deposition of blood lipids, chiefly cholesterol, on the artery wall causes an arteriosclerotic lesion. Recent advances in research in this field have cast light on the fact that particularly an elevation of low density lipoproteins (LDL), among blood lipids, plays a major role in arteriogenesis and that high density lipoproteins (HDL) are an antiarteriosclerotic factor contributory to the removal and degradation of the cholesterol taken up in the vascular wail and cell membrane and thus inhibitory to arteriogenesis.
Accordingly for the treatment and prevention of hyperlipidemia of various etiologies and arteriosclerosis and other diseases arising from hyperlipidemia, much work is underway for developing blood cholesterol lowering drugs and particularly drugs capable of reducing the blood level of low density lipoproteins and increasing that of high density lipoproteins.
However, the state of the art has so far failed to provide a fully satisfactory drug.
Under the circumstances the inventors of the present invention explored in earnest for compounds having potent lipid metabolism improving activity and found that S-(.alpha., .beta.-dicarboxyethyl)glutathione, which is a physiological substance, and its ester and amide derivatives have a strong lipid metabolism improving action. Based on the above finding, the present invention has been completed.